Knocking sound from the front wheels

Hi there

i'm driving a 2007 model MK1 Velociti 1.4 i .

when driving on smooth road, there is this knocking sound at the front wheels.

i can switch the car off as well, it is still there.

it is not the CV joints, and i replaced the top strut mounting, but still it is not gone.

Hope you people can help me. :?